Chuck



Jan. 16, 1923. 1,442,107. 1 M. VERNAZ.

CHUCK- FILED MAR. I5, I920- 2 $HEETS.SHEET 2.

FIG .3 I

FIG 5 I I I 1/ K I.

I g I I I l I I I I I I I I I I E I 1 l I (1/ I w 1 I I v VIZ Mam? l zz/z/ez zf/mample Patented Jan. 16, 1923. V

UNITED STATES MARCEL VERNAZ, OF LYON; FRANCE.

CHUCK.

Application filed March 16, 1920. Serial No. 366,226.

To (1U "wfiomit may concern Be it known that I THARC-EL Vnnxaz,mechanic, of Claudiennes, Lyon, i r'ance. have invented certain new anduseful Improvements in Chucks, of which the followingis a specification.

This inventionrelatcs to achuck with reversible jaws for lathes, boringmachines and all machine tools in general.

The chuck may comprise any suitable number of reversible jaws eachsodesigned that a single set of jaws is sufficient for gripping bars ofvery different thicknesses.

The tightening and loosening of the jaws is obtained by the action ofeccentric circular grooves or inclines which have the advantage ofoffering a large surface of support to the knobs of the axle pins of thejaws in all the positions of said jaws.

The annexed drawing illustrates an ex of construction of the improvedchuck.

Fig. 1 is a longitudinal section. Fig. ,2 is a front View, the fixingplate on the machine tool being removed.

Fig. 3 is a front view of the cage in which the bits slide, theposit-ion of the eccentric grooves being shown in dotted lines.

Fig. 4: is a front view of the disc showing the eccentric grooves orinclines.

Fig. 5 is an outer elevation of the chuck. v

Figs. 6, 7, and 8 are detail views respectively in front view, side viewand plan of the reversible jaws.

Fig. 9 is a detail view of the axle the jaws.

Fig. 10 is av plan view of a modification of the jaw.

a indicates a plate provided with a sleeve (4 for mounting the chuck onaxlathe, boring machine or other machine tool. On this plate is fixed byscrews 6 a circular cage 2) provided with radial slots 0 in which thejaws (Z slide.

These slots have interiorly on each face a small longitudinal tenonwhich engages in a corresponding mortice of the jaw and ensures perfectguiding of the latter.

In the interior of the cage 6 is adjusted a disk 6 turnable with slightfriction on the core 6 of the cage. This disk carries externallyhelicoidal teeth 6 engaging with a worm f, the trunnions f of which areembedded in a housing 9 provided for this purpose in the wall of thecage 6. The rotation pin of of the screw 7 is obtained from outside byinc-ans of a key engaged in the square-recess 7' with which one of thetrunnions f is provided- In order to facilitate the placing inpositionof the screw 7 the disc 6 has a cut-away portion 6 which when it isbrought opposite the screw allows of introducing the latter into itshousing or of withdrawing it at will. When the disc has made a certainrotation, the screw is held in of the, latter.

place by the rim On its inner face the disc 6 is provided with eccentriccircular grooves or inclines h each extending through an arc of 180 ineach of which is guided a knob 71 for moving the jaws. These knobs whichfollow the curves of the'grooves h are provided with pins 2' which serveas axles to the jaws d provided for this purpose with one or morehousings CF in which the said axles turn.

The working of the chuck is as follows By turning the screw f rotationof the disc 6 is produced the grooves h of which in acting on the knobs71 cause the simultaneous approach or separation of the jaws. It

is to be observedthat in this movement the knobs possess in all theirmovements a large surface of support in the grooves h, the knobs beingshaped to the curvature of the grooves. Further, the larger the piece tobe gripped between the jaws the slower and more powerful the pressure asthe curve of the grooves has atendency to become pro-' gressivelyparallel to the periphery of the disc in which they are formed. I

To facilitate the placing in position of the jaws the terminal openingsof the grooves, at the circumference, are of unequal widths. First oneknob (with its jaw) is introduced into the narrowest opening. The plate6 is then slightly turned and when the knob is sufficiently engaged inthe slot it cannot fall out, and need not be held in by hand even if theopening is facing downwards. Then the mandril is turned 120 throiigh thenext opening. The plate 6 is with its slot, and the mandril is givenanother turn of 120 wherein the third knob is inserted. The jaws arethen set, as usual by means of the worm 7. Without this device the bitswould require to be held by slots.

hand until sufficiently engaged with the To change the jaws it issufficient to adand the second knob is inserted again slightly turned,to engage this knob I just the disk 6 until the jaws come opposite theoutlets ff of the grooves then after giving them a hall turn on theaxles i of the knobs i to put them in place by a reverse movement of thedisc 6. When the jaws have several housings (Z for the'pins i (Fig. 10shows tWo by Way of example) it is possible by inserting the pins of therespective ja-Ws in one or the other or" said housings to mod= ity theextreme separation. of the jaws.

\Vhat I claim as my invention and desire to secure by Letters Patent orthe United States is Chuck for lathes, machine tools and the likecomprising a circular cage having a series of radial-guideways on itsouter face, means for attaching said cage to the lathe or the like, acore concentric with and Within said cage, a disk rotatable Within saidcage on said core, said disk being provided provided with one ormorebores, independent pins, the stems of which engage in said bores and theheads of which engage 1n said eccentric circular guideways, and meansfor imparting rotary movement to said disk from the exterior of saidcage whereby said jaws are slid. in said radial guidewa vs.

In Witness whereof I have signed this specification in the presence oftwo Witnesses.

MARCEL VERNAZ.

lVitnesses I JEAN GERMAIN, ALnxrs VERNAZ.

